try the people at
http://mpforum.freeforumsite.com/
or
http://www.smith-wessonforum.com/
seems the M&P is prone to the striker breaking just as the Sigma line is. btw I have 2 S&W sigma's brand new VE's both the strikers broke on them with less than 1,000 rounds through. heck my 9ve didnt even have more than 250 rounds.
broken 9ve striker
broke my (locking block/trigger/trigger spring/slide stop)pin in 40ve after getting the striker replaced.
broker 40ve striker
put 500 rounds through 40ve before striker broke got it back put 150 through it then pin broke. have had issues with pins walking out under recoil though some loctite helps. the pin that is placed in the middle of the trigger will walk also thats the worse one that could though any pin walking is bad.
S&W service is good and bad they pay shipping from your place and back send a shipping label atleast for us USA folk. 2 weeks turn around. btw when a striker breaks you have to send the gun in to get the striker replaced.
wish I bought me Steyr MA1's instead but wanted something with lousy heavy long trigger and good ergonomics.
precock on sigma is same as glock or close to it. M&P sear is different not sure how much.
M&P trigger weight is 5lbs though not as crisp as a Steyr nor as short.
M&P striker was not changed much from Sigma design. I think they make them out of MIM castings or a bad steel. it definately snaps like its overhardened and brittle.